A. Field of the Invention
The present invention relates to bending machines and more particularly to a channel bending machine which simultaneously bends both side walls of a "U" shaped metal channel.
B. Description of the Related Art
There is a number of well known bending machines for metal pieces such as wires, plates, etc., of the type wherein the metal piece is firstly bent by pressing such piece by means of a pressing member against a support member having a predetermined pattern.
With this type of machines a great variety of metal pieces can be manufactured, including channel shaped pieces of the type wherein a large metal plate is bent by its longitudinal edges usually at about 90.degree., which are used for multiple purposes such as in the automotive industry for the manufacturing of truck chassis or automotive chassis.
Sometimes, for some specific applications, the channel shaped piece have to be additionally bent by one or both side walls of the channel in order to give them for example a special "closed" channel shape, which is very difficult to carry out with the actual machines, because of the fact that the piece is already formed as a channel and is very difficult to adapt it at the actual components of the machines, firstly by one side and then by the other side.
One bending machine for forming "U" pieces such as rounded bars, channels, sections and the like, is disclosed in US. Pat. Nos. 4,798,073 and 4,890,469 both of Dischler, which comprises two opposed spaced bending devices, each including at least two bending components and drive means to move at least one of the bending components essentially transversely to the length of the piece to be bend.
To produce a rounded "U" shaped piece, the piece to be bent is placed between the bending components of each of the bending devices and then, a bending moment is applied by the bending components of two of the bending devices, acting transversely to the longitudinal axis of the piece. Due to the application of such bending torque the piece is bent in a rounded "U" shape piece.
Such machine, cannot produce pieces with side walls at 90.degree. and it is not possible to close the sides of the rounded "U" shaped piece or a channel in the same machine.
In the known art, although highly desirable, there is no machine which simultaneously could bend the plate as a "U" shaped channel, and then close the side walls thereof, mainly because there were no components to close the sides of the "U" shaped channel and there was no possibility to remove the closed channel from the support parts of the machine.
In other words, there is no machine available which be capable of simultaneously bend a metal plate as a "U" shaped channel, and then close one or both side walls thereof in a single machine in a single operation, mainly because there was no possibility to remove a closed channel from a support piece of the machine.
Considering the above referred problems, applicants developed a bending machine which simultaneously can bend both side walls of a "U" shaped channel to close one or the two side walls thereof, comprising: a support frame; a lower male member slide mounted on the support frame, having a two-halves male member, each half having a notch in lateral wall thereof, and is associated with driving means for opening the normally closed two halves of the male member when receiving a channel and releasing the channel once its side walls thereof have been closed inside each notch, allowing to remove it therefrom; and two lateral bending inserts each slide mounted on the support frame, and associated with driving means, for bending both side walls the channel into the notches. If desired an upper member, mounted on lowering and lifting means, is provided, having a blank holder to retain a channel on the lower male member when it is closed and/or a die member for simultaneously bend a plate forming a channel, and then close both side walls thereof forming a closed channel.
The bending machine of the present invention also can be combined with a channel forming machine in order to form a channel and then bending the sides of the channel.